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Mower Blades - How does their inertia affect your Ogura PTO clutch?

Mower Blades - How does their inertia affect your Ogura PTO clutch?

Sometimes it is interesting to find that some machine detail that seemed so trivial, has very deep importance. For example, what do the mower blades have to do with the life of a PTO clutch/brake? Surprisingly, a lot. When a mower manufacturer designs and builds a mower, there is much thought and testing put into it. PTO clutches with safety brakes are critical components, but they are also wear-components. When they engage at some speed, they wear a little bit each time. This is because they absorb some energy during every on/off cycle. That energy is based on two specific criteria: inertia and speed.

The inertia that we are concerned with is mainly based on those rotating blades. Afterall, the purpose of the PTO clutch brake is to start/stop those blades. Thick, long blades will have much more inertia than thin, short blades. So, by using longer, thicker, heavier blades, the cycle energy goes up and the wear increases as well. Think twice before trying to modify blades to get a different cut. Those were designed like that for a reason.

The best practice to limit wear on your PTO clutch brake is to slow down when engaging. In addition to inertia, energy is based on speed squared, so when you reduce the speed of the PTO shaft by 40%, you reduce the clutch and brake wear by about 64%.
Burnishing an Ogura clutch on a mower can offer several benefits including:

1 Engagement Time: Higher inertia in the system can increase the time it takes for the clutch to fully engage the mower deck / blades.

2 Wear and Tear: Inertia can also impact the wear and tear on the clutch components. Higher inertia means more work is required to accelerate or decelerate the mower deck / blades, potentially leading to increased stress on the clutch, engine, and belts over time.

3 Control System Design: Engineers designing equipment using Ogura clutches need to consider the effects of inertia in their controls and operation design. They may need to implement controls to compensate for inertia, such as using feedback control systems or Ogura Soft-Start Controllers to adjust clutch engagement parameters.

Overall, understanding the effects of mower blades and inertia is crucial in designing and operating systems that utilize Ogura clutches effectively and efficiently. It involves considering factors such as acceleration, response time, overall system performance, and life.

Benefits of using Ogura PTO clutch brakes on your mowers:
  • Quality of cut
  • Safety
  • Reliability of operation
  • More uptime (more time mowing)
  • Longer life of mower





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